The tasks performed by the operator of a computer have defined the devices through which input data is generated. In the case of a personal computer, a keyboard and a mouse are used.
Design and operation of computer peripherals maintains the difference between computers and other equipment such as radio, hi-fi and television. The requirement of a keyboard and mouse is becoming increasingly perceived as a major barrier to the wider use of computers in a much broader range of activities.
An example is the emergence of MP3 and other related audio compression standards. These provide high quality compression of audio data. Most radio stations around the world are now able to broadcast over the internet, in additional to their traditional location in the electromagnetic spectrum. Furthermore, it has become possible to store an entire CD collection on a low cost computer hard disk. However, the computer, in its present form, is not considered as a serious alternative to radio or hi-fi devices. A similar situation exists with video data. The preferred viewing device, except when editing, is a traditional television set.
Computers are increasingly capable of receiving and manipulating many different media types within a common, easily used, computer-generated environment. However, the method of supplying input to the computer terminal has restricted the wider use of this technology. The keyboard and mouse are best operated at a desk, and this prevents computers from being considered as replacements for a broad range of conventional electronic equipment. As computer and internet technology develops, increasingly the restrictions placed upon it are in the way the user interacts with computers through an input device.
The digitisation of graphic design, video and film editing has led to the development of improved devices for interaction with image data. The most widely used of input devices in this context is the graphics tablet, which is operated in the manner of a pencil-with-paper. On a large graphics tablet, it is possible to provide an area having the function of a keyboard, and this may be operated to generate occasional text where this required.
In three-dimensional computer modelling, no single preferred peripheral device has emerged. Several systems are known, optimised for particular applications. An example of this is radio tracking, which provides three dimensions of position and three dimensions of rotation. In a virtual reality application, a radio receiver is fixed to a users head-mounted display, and the position information obtained by analysing data from a fixed transmitter is used to determine stereoscopic images for the users eyes. The images are updated so as to provide an appropriate view for the angle and position of the user's head. Similar devices may be used to track the position of a hand, including devices that use ultrasound to determine orientation. Hand gestures resulting from finger movement may be tracked using a data glove. However, none of these devices is suitable for replacing a keyboard or mouse due to the requirement to suspend the devices in space in order to generate position data in the third dimension.
Graphics tablets and three dimensional input devices may be suitable for replacing the keyboard and mouse in certain applications. However, their high cost, and other practical considerations, make them unsuitable replacements for the widespread, low cost and ubiquitous keyboard and mouse of the personal computer.